Danny felt it had to do with the Dalai Lama being given a US award. China Protests US Award for Dalai Lama from the AP says "The United States has "gravely undermined" relations with China by giving the Dalai Lama an award, the Chinese government said Thursday."

I don't have to explain how important the Chinese market, including search market, is to the U.S. economy. I wonder what else China has up their sleeves.

Note, right now this is all speculation. China has not yet confirmed taking these actions. But I doubt Baidu has the power to redirect traffic at the ISP level.